Draft-gage.



A. STEINBART.

DRAFT GAGE. APPLICATION FILED AUG.16.1915. LQQ58$D Patented May15, 191?.

2 SHEE S-SHEET I.

F'EG. 2

wwmssas W Wm Z A.STHNBART;

DRAFT GAGE.

APPLICATION HLED AUG. 16. 1915.

Eatented May15,

2 SHEETS-SHEET w wE l Q i 4 wnTNEssEs J nan-an sra'rns PATENT @FFIIQE.

ALFREDSTEINBART, OF PITTSBURGH, PENNSYLVANIA.

DRAFT-GAGE.

Specification of Letters Patent.

Patented May 115, 1911?.

Application filed August 16, 1915. Serial No. 45,752.

To all whom itwnmy concern Be it known that I. ALrnnn STEINBART, a l 4 cltlzen of the United btates, and resident of Pittsburgh, 111 the county of Allegheny and State of Pennsylvania, have invented cer-- tam new and useful Improvements in Draft vision of a draft gage having a movable indicator which varies in weight with Variations in the extent of movement thereof.

1 Another object of the invention is the provision of a draft gage having novel means whereby variations in the draft of a stack are indicated and are made visible at a distance from the draft gage.

A further object of this invention is to provide a draft gage having novel means whereby difierences in the draft at separated parts of the apparatus in which a draft is maintained-are indicated and made visible.

A still further object of my invention is the provision of a draft gage having the novel combination and arrangement of parts to be more fully described hereinafter and to be specifically pointed out in the appended claims.

Referring now to the drawings forming part of this specification, F igure 1 is a front elevation showing one form of draft gage constructed and arranged in accordance with my invention.

Fig. 2 is a sectional side elevation of the apparatus shown in Fig. 1., the section being takeiron the line IIII of Fig. 1.

Fig. 3 is a sectional detail showing the construction of the weighted indicator forming part of my improved draft gage.

Fig. 4 is a front elevation, partly in sec tion, showing a modified form of draft gage constructed and arranged in accordance with my invention.

Fig. 5 is a sectional side elevation of the apparatus shown in Fig. 4, the section beii g taken on'the line V-V' of Fig. 4.

Fig. (3 is a sectional plan of the draft gage to project upwardly within the shown in Figs. 4 and 5, the section being taken on the line VI-VI of Fig. 4.

Fig. 7 is an elevation showing the draft gage of Figs. 4 and 5 as applied for use on a steam boiler fire place and stack.

In the accompanying drawings, referring now to the construction shown in Figs. 1 and 2, the numeral 2 designates a wall plate upon which the draft gage is mounted, and by which the gage is secured in operative position, and positioned on the front face adjacent to the ends ofthe wall plate 2 are Ts or fittings 3 and 4, eachhavinga nipple 5 or 6 screwed into the branch opening thereof.

The nipples extend through openings 7 and 8 in the wall plate 2, and screwed on the inwardly projecting ends of these nipples are elbows or fittings9 and 10. The Tsand the elbows are screwed .on the nipples 5 and 6 so as to bring the abutting faces thereof.

into tight holding engagement with the faces of the wall plate 2. Openings .11 in the wall. plate provide means for fastening the draft gage to awall or other support.

Extending lengthwise between the opposite ends of the Ts or fittings 3 and 4 is a glass tube 12, forming a transparent conduit. The ends of this conduit opening into the Ts 3 and 4. The tube or conduit is removably secured. to the Ts by the screw threaded sleeves or thimbles 18 and 14, which are screwed into the threaded outlets of the Ts, and the joints between the ends of the conduit and the sleeves 13 and 14, are made tight by suitable packing material.

The outlet at the lower end of the T 3 is closed by means of a threaded plug 15 and a stem 16. having a recessed flange 17 011 its upper end, is fastened to the plug 15 so as T 3'. The upper end of the T 4 also is closed by a threaded plug 18, and'a rod or stem 19 is secured to the plug to extend downwardly through the T 4 into the upper end of the conduit 12;

Positioned within the conduit 1'! is an indicator 2O which-is arranged to move within the conduit in indicating the draft or variations in the draft on the stack or other apparatus to which the draft gage is applied for use. The indicator 29 preferably is made of a thin sheet of aluminum cut and shaped to form a hollow cone .or frustum of a cone.

Upward movement of the indicator 20 1s limited by engagement thereof with the lower end of the stem 19 on the plug 18, and the recessed flange 17 of the stem 16 within the T 3 receives and supports the indicator when in its lowermost position within the tube 12. The large end of the indicator 20 which, as will be best seen in Fig. 3, is in the shape of a hollow cone or frustum of a cone, is slightly smaller in diameter than the internal diameter of the conduit 12, and secured to the small end of the indicator is a chain or similar flexible member 21 which forms a variable weight for the indicator 20. Care is taken to have the links of the chain 21 of equal size or weight, and the chain 21 is conveniently attached to the indicator 20 by means of a U-shaped clip 22 which is formed of wire with its free ends bent and projecting through the small end in the indicator. (See Fig. 3.)

Preferably the chain 21 is arranged in a double strand with a separator or spreader bar 23 to hold the two strands apart in the manner shown, this construction tending to prevent rotation of the indicator 20 within the conduit 12, when the opening in the conduit is cylindrical in cross section as shown. Obviously, however, a single strand of chain may be employed instead of the double strand shown. The lower end or ends of thedepending chain 21 may be fastened to the flange 17 on the,stem 16in the T 3 when desired, and when connected in this manner to the flange 17, the stem 19 at the top of the gage glass, may be omitted.

The face of the wall plate 2 preferably is graduated in the manner shown in Fig. 1, and fingers like those shown in Fig. 1 may be employed to show the proper position of the indicator and relatively any fluctuations in the draft of the stack, furnace, or apparatus to which the gage is applied for use. A pipe 24 screwed into the elbow 10 is em ployed to connect the upper end of the draft gage to a stack or other apparatus to which the gage is applied, and a similar pipe 25 screwed in the elbow 9 on its lower end connects the bottom of. the gage with the atmosphere at a suitable point.

In the operation of the draft gage shown in Figs. 1 and 2, the pipe 24 leads into the interior of the stack of the apparatus to which the gage is applied for use.

The heated stack gases at thebottoni of the stack have a pressure less than atmospheric pressure, and as the upper. end of the glass conduit 12 is connected by the pipe 24- with the interior of the stack, near its base,

the pressure within the conduit above the in-- dicator 20 will also be less than atmospheric pressure.

The conduit 12 below the indicator 20 being connected at its lower end to the pipe 25 which opens into the atmosphere will be at atmospheric pressure and, owing to the pressure below the indicator 20 being greater than that in the stack to which the upper end of the conduit 12 is connected, the unbalanced pressures cause the indicator or.

cone 20 to rise within the conduit 12. H

The higher the indicator is lifted inthe conduit, the greater the amount of the chain 21 or equivalent flexible weight suspended from the indicator 20 that is lifted by the indicator from the recessed flange 17 on the upper end of the stem 16, upon which it:

flange 17 counter-balances the difference in pressure of the stack gases from atmospheric pressure.

This difference in pressure is the stack;

draft and it will be apparent that as. the

stack draft increases the indicator will lift higher in the conduit 12 and therefore that the position of the cone within the conduit relative to the ends of the conduit or'the graduations on the face of the wallplate 2 will show the degree or extent of the draft at the lower end of the stack to which the gage is applied for use.

It should be noted that with'the construction shown in Figs. 1. and 2 some portionof the chain 21 or equivalent flexible weight suspended from the indicator 20 will be su p' jz' ported upon the recessed flange 17 within, the T 3 at all times, or until the indicator}2 when in its highest position, engages the stem 19 on the plug 18. U

As the indicator 20 fits loosely within the conduit 12 a small amount of air or other gas leaks. at all times from the lower to the higher side of the indicator and flows through the pipe 21 into the stack, so that in this way the dirty stack gases are prevented from moving backwardly into the transparent conduit 12.

It will be obvious that when the pipe 25 leading to the lower end of the conduit 12 is connected to an air line or pipe for conducting air under pressure, as for examplefrom a fan or blower to a forced draft furnace, and the pipe 2 1 on the upper end of the conduit 12 is opened to the atmosphere, the indicator 20 will register and show the pressure of the air flowing through the air line to the forced draft furnace. I

In Figs. 4, 5, 6, and 7, a modified construction is shown, in which two lengthwise vertical glass tubes or conduits 12, 12"., are employed. The lower end of the glass tube 12 is secured in the upper end of the T 3 outlet of the T 27.

1 senses sleeve or thimble 13 and the upper end of the tube 12 is fastened by a similar sleeve or thimble 11 in the lower end of the T r The lower ends of the Ts 3 3 and upper end of the T5 49, r are closed by plugs 15 and 15", 18 and 18". (See Figs. 5 and 6.) The Ts 3 and t to which the glass tube 12 is attached are single outlet Ts and the Ts 3 and a to which the tube 12 is attached are side outlet Ts 6., Ts having two side outlets which extend axially at right angles) Screwed into one outlet of the Ts 3 and at are short nipples 5 6, and

screwed into one outlet of the PS 3' and 4c are similar nipples 5", 6". The nipples 5, 6, and 5, 6", project through openings 7, S, and 7 8 in the wall plate 2 The elbows-9 10*, are screwed on the nipples 5 5 and an elbow. 9 is screwed on the nipple 5 These elbows and coupling 33 screwed on the nipple i3" serve to rigidly fasten the Ts 3, 45*, 3 and at in place on the wall plate 2. A plug 345 closes one end of the coupling 33.

Also secured on the wall plate 2 are side outlet Ts 26 and 27 similar to the side outlet Ts 3 and at". The lower end of the T 26 is connected to a pipe 30 and the upper end of the T 27 is connected to a pipe 31. The upper end of the T 26 is connected to the lower end of the T 27 by a pipe and one (the upper) end of the pipe 35 is closed by means of a plug 36 which prevents passage of fluid through the pipe 35, the pipe in the construction shown closing the upper end of the T 26 and lower end of the T '27, and forming a convenient support for the fingers 37 and 38 adj ustably secured thereon. (See Fig. 4.)

The fingers 37 and 38 extend into proximity to the lengthwise parallel vertical tubes 12 and 12 and serve to indicate the height at which the conical indicators 20 and 20 should be maintained and show variations from the draft which should be maintained.

One of the two side outlets in each of the Ts 26 and 27 has short nipple 32 screwed therein and these nipples extend through holes 7, 8, in the wall plate 2 A coupling 33 having a plug 31 closing one end thereof is screwed on each of the nipples32 to secure the side outlet Ts 26 and 27 in position on the wall plate. (See Fig. 6.)

One side outlet of the T 3 is connected to one side outlet of the T 26 by a nipple 2S, and one side outlet of the T 4" is in the same manner connected by a nipple 28to one side (See Figs. 4 and 5.)

One outlet of the elbow 10 on the upper end of the conduit 12. is connected by a diagonal pipe 39 to the elbow 9" which is connected to the lower end of the conduit lower end of the conduit 12 is provided which leads into the branch outlet of a'T 51.

with a short pipe 40, the lower end of which is open to the atmosphere.

Mounted in the glass tubes forming the conduits 12 and 12 are indicators 20 and 20 each of which is provided with a chain or flexible weight :21 which is connected to the indicators in the same manner as described in connection with the construction shown in Figs. 1 and 2.

The lower ends of the Ts 3" and 3 are closed by plugs 15 and 15", stems 16 16, being secured to the plugs in the same manner as that shown and described in connection with Figs. 1 and 2, and the Ts 1 and 1 on the upper end of the gage glasses 12 and 12 have stems 19, 19 projecting down wardly from the plugs 18 and 18 which close one outlet on the Ts 1 and 4 The apparatus of Figs. 1, 5 and 6 is shown in Fig. 7 as secured in place on a steam boiler furnace i2. As will be seen in Fig. 7, the wall plate 2 is fastened by straps ll, 41, to the front face of the boiler furnace. The furnace as shown is provided with a stack l3 having a damper 1-1 therein, and the pipe 31 of the draft gage of Figs. 4t, 5 and (3 is connected at one end to a valve The valve 4.5 is also connected witha pipe a6 which in turn is connected by an elbow 17 to a pipe 41-8 which opens into the stack 43 at a point below the stack damper at.

The pipe 30 connected to the sideoutlet T 26 is connected to a valve 49 and this valve is secured on one end of a pipe 50 The other outlets on the T 51 connect one to a pipe 52 leading to the interior of the boiler furnace above the grate bars of the furnace, and the other to a pipe 53 having a cap 54 on one end with two small holes in the cap opening into the atmosphere. I

In the operation of the draft gage shown in Figs. 4,, 5, 6, and 7, the apparatus is applied for use in the manner shown in Fig. 7.

The pressure of the products of combustion or gases in the boiler furnace is less than atmospheric pressure and the loWer end of the conduit 12 of the draft gage, being connected to the furnace, has the sam. pressure as within the furnace, which acts on the lower side of the indicator 20 The pressure of the furnace gases also acts on the upper end of the indicator 20 in the conduit 12 as the lower end of the conduit 12 and the connections from the furnace are connected through the diagonal pipe 39 with the upper end of the conduit 12 The lower end of the conduit 12 is open to the atmosphere through the pipe 40 so that there is atmospheric pressure within the conduit 12 below the indicator 20 The atn'iospheric pressure. in the conduit 12 being greater below the indicator 20 than the pressure above this indicator, the indicator, which has achain or flexible 130 weight as in Figs. 1 and 2, is caused to rise within the conduit 20* a distance which varies with the difference in pressure on opposite sides of the indicator and by the extent of such lifting movement relative to the ends of the conduit 12 indicates the difference in. pressure which represents the draft within the furnace.

The gases within the stack at the lower end of the stack have a still lower pressure than that within the furnace, and, as the upper end of the conduit 12* connects into the stack through the pipe 31, valve 45', and

pipes 46 and 48, this end of the conduit 12 above theindicator 'will have the stack pressure acting on the top of the indicator 20". The pressure in the lower end of the conduit 12" below the indicator 20 being connected to the boiler furnace, acts upon holes 55 in the cap 54 on the pipe 53 to prevent heated or dirty gases backing up into the conduits of the draft gage. From the above description it will be clearly seen, that the indicator in the conduit'12 will indicate or show the furnace draft and that the indicator 20* in the conduit 12 will show the loss in draft due to friction of the products -offcombustion or. heated gases while traveling from the furnace through the boiler into the stack. As to obtain the most economical operation of the boiler it is necessary for the furnace draft and loss of draft in the passage of the gases through the boiler flues to the stack to be maintained at a. certain difference or ratio, the draft gage of Figs. 4 to 7 shows the boiler fireman when this desired result is being obtained and being maintained through the. operation of the fire bed, furnace grate and stack damper.

By testing the apparatus under suitable conditions and setting the pointers or fingers 37 and 38 at such time, the desired position of the indicators 20 and 20 will be obtained so as to show unskilled workmen when the proper draft is within the furnace and in the stack.

The advantages of my invention will be apparent to those skilled in the art. By the.

use of my improved draft gage a mechanically operating appliance is provided which shows visually the operations in the;

draft of,boilers, furnaces, and similar apparatus. The use of the ordinary U-tube and water or mercury gage is avo ded. By graduating the wall plate of my improved gage in the manner shown, the amount of the draft in terms of weight or distance may be indicated, and by adjusting the fingers of the apparatus shown in Fig. 4;, when such fingers are used, the positions'at which the draft indicators should be maintained is shown, so ordinary laborers employed in firing steam boilers can maintain the required draft on the stack and on the fuel in the boiler furnace by regulating the firing operations, furnace doors, and staclr damper, to keep the indicators opposite the indicator fingers.

The construction of the gage is simple, the gage is extremely sensitive, and is not easily afi'ected by heat or changes in temperature, and it is easily constructed and maintained -in operative condition without expensive. repairs or delays 1n operation caused by making repairs.

Modifications in the construction and arrangement of parts may be made without departing from my invention as defined in the appended claims.

I claim 1. A draft gage comprising a transparent conduit having fluid pressure inlet and outlet openings and an indicator-movable within and visible from the exterior of the conduit, said indicator having means connected thereto, and inclosed within the' conduit whereby theweight acting upon the indicator is varied with changes in theposition of the indicator within said conduit caused by the pressure of fluid within the tube.

2. A draft gage comprising a transparent conduit having fluid pressure inlet and out-' let openings and an indicator movable with: in and visible from the exterior of the conduit, said indicator having means connected thereto and inclosed within the conduit whereby the weight acting upon the indicator increases when moved in one direction by'fiuid pressure within the conduit.

3. A draft gage comprising a vertical transparent conduit having fluid pressure inlet and outlet openings and a movable indicator within said conduit, said indicator having means connected thereto and inclosed within the conduit Whereby..-t'he weight acting upon the indicator increases when lifted by fluid pressure within the conduit.

4. A draft gage comprising a transparent conduit having fluid pressure inlet and outlet openings, a movable indicator within said conduit, said indicator having flexibly joined elements suspended therefrom whereby the weight acting on the indicator increases with increase in the extent of lifting movement thereof, and means forming a support for 'unlifted portions of said flexibly joined ele ments.

5. A draft gage comprising a transparent conduit having fluid pressure inlet and outlet openings, a movable indicator within said conduit, said indicator having a chain suspended therefrom whereby the Weight acting on the indicator is increased when lifted by fluid pressure within said conduit and a support for unlifted portions of said chain 6. A draft gage comprising a vertical transparent conduit having fluid pressure inlet and outlet openings, and a conical indicator arranged to be lifted within the conduit by the action of fluid pressure therein and having means for varying the weight to be lifted with changes in the extent of lifting movement of the indicator, said indicator being visible through the transparent conduit andshowing fluctuations in the pressure of fluid within the conduit by variations in the extent of lifting movement of said indicator.

7. A draft gage comprising parallel conduits, a movable indicatorgwithin each coni duit, said indicators being visible from the exterior of the conduits and having means connected thereto and inclosed within the conduits whereby the weight acting upon the indicators increases with the extent of lifting movement. of the indicators, and said conduits having inlet and outlet openings therein, the inlet in'one conduit opening into the atmosphere, means connecting the outlet in said conduit to the inlet in the second conduit and adapted to connect said outlet to an inclosure, an outlet in said second conduit, and means connected to the outlet in said second conduit for creating a draft within the conduits.

8. A draft gage comprising parallel, transparent 60116111175, a movable indicator within each conduit, said indicators having means connected thereto and inclosed within the conduits whereby the weight acting upon the indicators increases with the extent of lifting movement of thgindicators, and said conduits having inlet and outlet openings therein, the inlet in one conduit opening into the atmosphere, means connecting the outlet in said conduit to the inlet in the second conduit and adapted to connect said outlet with an inclosure and to the atmosphere, and means connected to the outlet in the second conduit for creating a draft Within the conduits.

9. In a furnace draft gage, the combination with a furnace and a stack connected thereto, of a gage having vertical transparent conduits, a movable indicator within each conduit, said indicators having means connected thereto and inclosed within the conduits whereby the weight acting on the indicators increases with the extent of lifting movement thereof, said conduits having inlets and outlets therein, the inlet in one conduit opening into the atmosphere, means for connectingthe outlet in said conduit to the inlet of the second conduit, means for connecting the inlet of said second conduit with the furnace, and means for connecting the outlet in said second conduit to the stack of said furnace.

10. In a furnace draft gage, the combination with a furnace'and a stack connected to said furnace, of a gage having vertical transparent conduits, a movable indicator within each-conduit, said indicators having means connected thereto and inclosed within the conduits whereby the weight acting on the indicators increases with the extent of lifting movement thereof, said conduits having inlets and outlets therein, the inlet in. one

with the furnace and with the atmosphere,

and means for connecting the outlet in said second conduit to the stack of said furnace.

11. A draft gage comprising a conduit having a fluid pressure inlet and outlet, an indicator movable within and visible from without said conduit, and means inclosed. within the conduit and connected to said in dicator whereby the weight acting on the indicator is varied with increases in the extent of the lifting movement thereof caused by fluid pressure acting upon said indicator.

12. A draft gage comprising a conduit having a fluid pressure inlet and outlet, an indicator movable within and visible from without said conduit, and means inclosed within the conduit and connected to said in-- dicator whereby the weight acting to restrain lifting movement of the indicator is increased with increases in the extent of the lifting movement thereof caused by fluid pressure acting upon said indicator.

13. A draft gage comprising a transp a rent conduit having a fluid pressure inlet and outlet, a conical indicator movable within said conduit by the action of fluid pressure therein said indicator being visible from the exterior of the conduit to thereby indicatefluctuations in the pressure of the fluid withpressure inlet and outlet, and means mov ably mounted in said conduit and arranged to lift within the conduitby the action of the gaseous fluid pressure therein to indicate fluctuations in pressure of the gaseous fluid, said means being constructed and arranged to vary the weight acting on the in-' dicator with increases in the distance said means is lifted.

15. A draft a e com risin a trans Jar- I- D b D ent conduit having fluid pressure inlet and outlet openings, a conical indicator within v movement thereof, and a stop at one end of said conduit to limit the movement of said indicator and adapted to form a support for unlifted portions of said flexibly joined elements.

16. A draft gage comprising a cylindrical glasstube having fluid pressure inlet and outlet openings adjacent to the ends thereof,

and a movable indicator within the tube, said indicator having means connected thereto and inclosed within the tube whereby the weight acting upon the indicator increases With the extent of lifting movement of the indicator.

17. A draft gage comprising a cylindrical glass tube having fluid pressure inlet and outlet openings adjacent to the ends thereof, a movable indicator within the tube, said indicator having means connected thereto and inclosedwithin the tube whereby the weight acting upon the indicator increases with the extent of lifting movement of the indicator, and means at the ends of said conduit forming stops to limit the travel of the indicator in said tube.

18. A draft gage comprising a cylindrical glass tube having fluid pressure inlet and outlet openings adjacent to the ends thereof,

a movable indicator within the tube, said indicator having means connected thereto and inclosed Within the tube whereby the weight acting upon the indicator increases with the extent of lifting movement of the Gepflea of thia patent may be obtained for indicator, and means at the ends of said conduit forming stops to limit the travel of the indicator insaid tube, the lowermost of said stops forming av support for unlifted portions of the weight varying means on said indicator.

19. A draft gage comprising a cylindrical glass tube having fluid pressure inlet and outlet openings adjacent to the ends thereof, a movable indicator within the tube,- said indicator having means connected thereto and inclosed within the tube whereby the weight acting upon the indicator increases with the extent of lifting movement of the indicator, and an index fingeron said gage to mark the position of the indicator when a: predetermined amount of draft is being elements, and an index finger on said gage to mark the position of said indicator when a predetermined amount of draft is being obtained.

In testimony whereof I have hereunto set my hand. a V ALFRED STEINBART.

Witnesses E. O. Romtninn, BRYANT 'BANNISTER.

five centa each, by addressing the Oommtaaiener of latente.

Washington, D. Q." 

